1 /* Darwin/powerpc host-specific hook definitions.
2 Copyright (C) 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
3
4 This file is part of GCC.
5
6 GCC is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published
8 by the Free Software Foundation; either version 2, or (at your
9 option) any later version.
10
11 GCC is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
14 License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING. If not, write to the
18 Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
19 MA 02110-1301, USA. */
20
21 #include "config.h"
22 #include "system.h"
23 #include "coretypes.h"
24 #include <signal.h>
25 #include <sys/ucontext.h>
26 #include "hosthooks.h"
27 #include "hosthooks-def.h"
28 #include "toplev.h"
29 #include "diagnostic.h"
30 #include "config/host-darwin.h"
31
32 static void segv_crash_handler (int);
33 static void segv_handler (int, siginfo_t *, void *);
34 static void darwin_rs6000_extra_signals (void);
35
36 #ifndef HAVE_DECL_SIGALTSTACK
37 /* This doesn't have a prototype in signal.h in 10.2.x and earlier,
38 fixed in later releases. */
39 extern int sigaltstack(const struct sigaltstack *, struct sigaltstack *);
40 #endif
41
42 /* The fields of the mcontext_t type have acquired underscores in later
43 OS versions. */
44 #ifdef HAS_MCONTEXT_T_UNDERSCORES
45 #define MC_FLD(x) __ ## x
46 #else
47 #define MC_FLD(x) x
48 #endif
49
50 #undef HOST_HOOKS_EXTRA_SIGNALS
51 #define HOST_HOOKS_EXTRA_SIGNALS darwin_rs6000_extra_signals
52
53 /* On Darwin/powerpc, hitting the stack limit turns into a SIGSEGV.
54 This code detects the difference between hitting the stack limit and
55 a true wild pointer dereference by looking at the instruction that
56 faulted; only a few kinds of instruction are used to access below
57 the previous bottom of the stack. */
58
59 static void
segv_crash_handler(int sig ATTRIBUTE_UNUSED)60 segv_crash_handler (int sig ATTRIBUTE_UNUSED)
61 {
62 internal_error ("Segmentation Fault (code)");
63 }
64
65 static void
segv_handler(int sig ATTRIBUTE_UNUSED,siginfo_t * sip ATTRIBUTE_UNUSED,void * scp)66 segv_handler (int sig ATTRIBUTE_UNUSED,
67 siginfo_t *sip ATTRIBUTE_UNUSED,
68 void *scp)
69 {
70 ucontext_t *uc = (ucontext_t *)scp;
71 sigset_t sigset;
72 unsigned faulting_insn;
73
74 /* The fault might have happened when trying to run some instruction, in
75 which case the next line will segfault _again_. Handle this case. */
76 signal (SIGSEGV, segv_crash_handler);
77 sigemptyset (&sigset);
78 sigaddset (&sigset, SIGSEGV);
79 sigprocmask (SIG_UNBLOCK, &sigset, NULL);
80
81 faulting_insn = *(unsigned *)uc->uc_mcontext->MC_FLD(ss).MC_FLD(srr0);
82
83 /* Note that this only has to work for GCC, so we don't have to deal
84 with all the possible cases (GCC has no AltiVec code, for
85 instance). It's complicated because Darwin allows stores to
86 below the stack pointer, and the prologue code takes advantage of
87 this. */
88
89 if ((faulting_insn & 0xFFFF8000) == 0x94218000 /* stwu %r1, -xxx(%r1) */
90 || (faulting_insn & 0xFC1F03FF) == 0x7C01016E /* stwux xxx, %r1, xxx */
91 || (faulting_insn & 0xFC1F8000) == 0x90018000 /* stw xxx, -yyy(%r1) */
92 || (faulting_insn & 0xFC1F8000) == 0xD8018000 /* stfd xxx, -yyy(%r1) */
93 || (faulting_insn & 0xFC1F8000) == 0xBC018000 /* stmw xxx, -yyy(%r1) */)
94 {
95 char *shell_name;
96
97 fnotice (stderr, "Out of stack space.\n");
98 shell_name = getenv ("SHELL");
99 if (shell_name != NULL)
100 shell_name = strrchr (shell_name, '/');
101 if (shell_name != NULL)
102 {
103 static const char * shell_commands[][2] = {
104 { "sh", "ulimit -S -s unlimited" },
105 { "bash", "ulimit -S -s unlimited" },
106 { "tcsh", "limit stacksize unlimited" },
107 { "csh", "limit stacksize unlimited" },
108 /* zsh doesn't have "unlimited", this will work under the
109 default configuration. */
110 { "zsh", "limit stacksize 32m" }
111 };
112 size_t i;
113
114 for (i = 0; i < ARRAY_SIZE (shell_commands); i++)
115 if (strcmp (shell_commands[i][0], shell_name + 1) == 0)
116 {
117 fnotice (stderr,
118 "Try running '%s' in the shell to raise its limit.\n",
119 shell_commands[i][1]);
120 }
121 }
122
123 if (global_dc->abort_on_error)
124 fancy_abort (__FILE__, __LINE__, __FUNCTION__);
125
126 exit (FATAL_EXIT_CODE);
127 }
128
129 fprintf (stderr, "[address=%08lx pc=%08x]\n",
130 uc->uc_mcontext->MC_FLD(es).MC_FLD(dar),
131 uc->uc_mcontext->MC_FLD(ss).MC_FLD(srr0));
132 internal_error ("Segmentation Fault");
133 exit (FATAL_EXIT_CODE);
134 }
135
136 static void
darwin_rs6000_extra_signals(void)137 darwin_rs6000_extra_signals (void)
138 {
139 struct sigaction sact;
140 stack_t sigstk;
141
142 sigstk.ss_sp = xmalloc (SIGSTKSZ);
143 sigstk.ss_size = SIGSTKSZ;
144 sigstk.ss_flags = 0;
145 if (sigaltstack (&sigstk, NULL) < 0)
146 fatal_error ("While setting up signal stack: %m");
147
148 sigemptyset(&sact.sa_mask);
149 sact.sa_flags = SA_ONSTACK | SA_SIGINFO;
150 sact.sa_sigaction = segv_handler;
151 if (sigaction (SIGSEGV, &sact, 0) < 0)
152 fatal_error ("While setting up signal handler: %m");
153 }
154
155
156 const struct host_hooks host_hooks = HOST_HOOKS_INITIALIZER;
157